HOUSTON (AP) — As a parade of motorists rolled down their windows on the edges of a Houston Home Depot parking lot offering cash, the crowd of day laborers had slowly thinned to about a dozen by mid-morning.

The workers who were already gone were off to tear out soggy carpeting, carry ruined sofas to the curb and saw apart mold-infested drywall. Those who still remained knew they were hot commodities and weren't going to settle for low offers.

The owner of a car dealership shook his head and drove off after his $10-an-hour proposal to clean flooded vehicles drew no takers. A pickup driver who...